After being sent out on an errand to buy Post-It notes for his boss, the unnamed intern decided to slip a little note in there himself – according to this Reddit thread.

Cunningly, he put he note mid-way through the pad, so his boss would only find it after he had completed his allotted time at the unnamed firm.

This Post-It note seems innocent enough at first.

But have a little flick through to the back…

Let’s take a closer look… oh.

Yup, the intern must have been pretty p*ssed off with that guy.

Seriously though, spitting in someone’s coffee?

The intern’s boss, who goes by the name Win_in_Raom on Reddit, uploaded photographs of the Post-It notes online with the comment: ‘We sent out our intern to buy sticky notes. He’s not a very bright kid.’